[PATCH 0/2] more rcu_read_(un)lock conversions

[PATCH 0/2] more rcu_read_(un)lock conversions

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Hi,
  Two more rcu_read_(un)lock conversions around
virtio stuff.
(to go with, but independent of my previous 'virtio: Use auto rcu_read macros')

I like the way that the virtio-net case simplifies the function
a lot.

Dr. David Alan Gilbert (2):
  virtio/vhost: Use auto_rcu_read macros
  virtio_net: use RCU_READ_LOCK_GUARD

 hw/net/virtio-net.c | 7 ++-----
 hw/virtio/vhost.c   | 4 +---
 2 files changed, 3 insertions(+), 8 deletions(-)

-- 
2.23.0

[PATCH 1/2] virtio/vhost: Use auto_rcu_read macros

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use RCU_READ_LOCK_GUARD instead of manual rcu_read_(un)lock

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/virtio/vhost.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 99de5f196f..4da0d5a6c5 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -924,7 +924,7 @@ int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write)
     uint64_t uaddr, len;
     int ret = -EFAULT;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     trace_vhost_iotlb_miss(dev, 1);
 
@@ -956,8 +956,6 @@ int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write)
     trace_vhost_iotlb_miss(dev, 2);
 
 out:
-    rcu_read_unlock();
-
     return ret;
 }
 
-- 
2.23.0

[PATCH 2/2] virtio_net: use RCU_READ_LOCK_GUARD

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use RCU_READ_LOCK_GUARD rather than the manual rcu_read_(un)lock call.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/net/virtio-net.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 9f11422337..80622861a8 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1369,12 +1369,9 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
 static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
                                   size_t size)
 {
-    ssize_t r;
+    RCU_READ_LOCK_GUARD();
 
-    rcu_read_lock();
-    r = virtio_net_receive_rcu(nc, buf, size);
-    rcu_read_unlock();
-    return r;
+    return virtio_net_receive_rcu(nc, buf, size);
 }
 
 static void virtio_net_rsc_extract_unit4(VirtioNetRscChain *chain,
-- 
2.23.0

Re: [PATCH 0/2] more rcu_read_(un)lock conversions

[Michael S. Tsirkin]

On Fri, Oct 25, 2019 at 11:34:01AM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Hi,
>   Two more rcu_read_(un)lock conversions around
> virtio stuff.
> (to go with, but independent of my previous 'virtio: Use auto rcu_read macros')
> 
> I like the way that the virtio-net case simplifies the function
> a lot.

Indeed, I'll queue this.

> Dr. David Alan Gilbert (2):
>   virtio/vhost: Use auto_rcu_read macros
>   virtio_net: use RCU_READ_LOCK_GUARD
> 
>  hw/net/virtio-net.c | 7 ++-----
>  hw/virtio/vhost.c   | 4 +---
>  2 files changed, 3 insertions(+), 8 deletions(-)
> 
> -- 
> 2.23.0